Objective: The aim of this study was to evaluate whether a 12-week remotely delivered walking program based on selfdetermination theory (SDT) improves autonomous exercise motivation in adults with mild traumatic brain injury (mTBI) versus an active control and whether baseline psychological resilience moderates the treatment effect on motivation. The secondary objective was to examine effects on controlled motivation and resilience. Setting: The study was conducted at outpatient neurosurgery clinics at a medical center in Taipei, Taiwan. Participants: Seventy-three adults aged$20 years with mTBI were randomized to the intervention (n 5 38) or active control health education (n 5 35) group. Design: This study was a single-center, single-blind, parallel-group randomized controlled trial with concealed block randomization and intention-to-treat analyses. Interventions: A 12-week remote walking program was implemented using a wearable fitness bracelet and weekly LINE messages that support SDT needs. Main measures: The primary outcome was autonomous exercise motivation, measured using the Chinese Sport Motivation Scale-II. Secondary outcomes were controlled motivation and psychological resilience, measured using the Resilience Scale for Adults. Outcomes were assessed at baseline and at 3 and 6 months after the intervention. Results: Autonomous motivation did not differ significantly between groups at either postintervention assessment. Controlled motivation increased significantly in the intervention group at 6 months relative to baseline (B 5 1.05, 95% CI 5 0.13–1.97, P 5 .03). No between-group difference was observed in resilience. Baseline psychological resilience significantly moderated the treatment effect on autonomous motivation (B 5 0.05, 95% CI 5 0.01– 0.08, P 5 .018). Controlled motivation exerted no moderation effect. Conclusion: The remote walking program did not increase autonomous motivation on average, but controlled motivation was higher at 6 months. Higher baseline resilience strengthened the program’s effect on autonomous motivation. Screening for resilience and integrating resilience-building components may enhance motivational benefits and support long-term adherence in rehabilitation.